1. Field of the Invention
The present invention relates to a light-emitting device using an oxide, and particularly using an organic EL element and an inorganic EL element. The light-emitting device according to the present invention also relates to a top emission type or a bottom emission type.
2. Related Background Art
In recent years, a flat panel display (FPD) is in practical use as a result of the progress of technologies relating to a liquid crystal and electroluminescence (EL). The FPD is driven by an active matrix circuit consisting of a field effect thin film transistor (TFT) using an amorphous silicon thin film or a polycrystalline silicon thin film provided on a glass substrate as an active layer.
On the other hand, an attempt has been made to use a lightweight and flexible resin substrate in place of the glass substrate, in quest of further improvement in thinning, slimming and breakage resistance of an FPD. However, because a thermal process in a comparatively high temperature is necessary to manufacture a transistor with the use of the above described silicon thin film, it is difficult to directly form the silicon thin film on a resin substrate with low heat resistance.
For this reason, a TFT using an oxide semiconductor thin film mainly containing ZnO for instance, which can be film-formed at a low temperature, has been actively developed (Japanese Patent Application Laid-Open No. 2003-298062).
However, the TFT using a conventional oxide-semiconductor thin film does not reach a technical level of developing the applied technology, probably because of not having attained sufficient characteristics such as in a TFT using silicon.